Interesting concept. The name escapes me, but there is a platform where users get rewards for feedback and discussions. There are also several review rewarding startups on the blockchain like Futourist.io.

Social media: There are some new players but many have really failed to design a solid product. Sphere, OnG Social, LBRY (video sharing but social-network-ish), don't look like contenders at all. The real player, once it's ready, will be EOS' version of Steemit.